Hand-generator for harmonic signaling systems.



R. HCMANSON HAND GENERATOR FOE HARMONIG SIGNALING SYSTEMS.

APPLICATION FILED MAB-.16, 1907.

Patented July 16, 1912.

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HAND GENERATOR FOR HARMONIG SIGNALING SYSTEMS.

APPLIOATION FILED MAR. 16, 1907.

Patented July 1% 3912.

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Suva H You affoznu R. H. MANSON. HAND GENERATOR FOR HARMONIG SIGNALING SYSTEMS. APPLIOATION rI'LED MAR. 16, 1907.

ii fiaaaaso Patented 51113136, 19112.

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- hurrah sraiin s ,3, astray, a al ar?- @"mrn m -rr l2 it) t RAY H. MANSON, 0F ELYRIA, OHIO, ASSIGNOR TO THE DEAN ELECTRIC COMPAFS: '1", OF ELYRIA, OHIO, A CORPORATION OF 015.10.

HAND-GENERATOR FOR, HARMONIC SIGNALENG ELAN-52,688.,

monic Signaling Systems of which the 01- lowing is a specification, reference being had therein to the accompanying drawing.-

This invention relates to telephone sys-.,'

tems and especially to harmonic signaling systems. p v It has for its ObjQCtthe production of means whereby an annunciator or indicator may be actuated from asubstation or other point on a line, without actuating any of the ringers at the subscribers stations.

The invention 1s particularly appllcable to what are known as rural or farmers lines, whereof the length and resistance are too great to permit of the use of common battery, and therefore the old fashioned magneto hand generator is employed for purposes of signaling. At the central station constituting the. terminus of such a line the operator is provided with ringing generators as used in all systems; and .at the substations, the hand-generators are located usuhllyin. open bridges of the line,closed when signaling.

hen ordinary hand generators are used in the manner indicated, with harmonic ringers, there is a strong tendency for the low frequency ringers to be actuated every time a subscriber is calling central. By low frequency ringers in this case I particularly refer to the 16 and 83 cycle ringers, where the complete set of frequencies employed are:16,,33, 50, (38. Of course'these fre quenci'es may be made anything desired, but are referred to herein because they are standard.

Tlhe present design consists specifically of a cm'nmutator arrangement adapted to regulate the current from the hand generator,

so as to prevent its ringing any of the "bells at the substations when signaling the 6X? change for" aconnection or when clearing out.

I have found that an ordinary alternatingcurrent I bell even wnen the hue terminatesin a 1 0O eneratorwill operate the 16 cycle ohm annunciator a t the switchboard. This true-when a-low Voltage generator is used,

Specification of Letters Patent.

I hating current.

.mer application, Serial No.

SYSTEMS.

Divided this application filed March such as a three bar alternating current generator with one magnet reversed so as to neutralize one of the other magnets and give in eilect a one bar generator. I have also found that three bar direct current generators and pulsating current generators will operate thelow frequency harmonic ringers. A special drum wound armature With large number-of commutator segments will not-do this but the cons ruction cannot be carried to this point onaccount of expense in manufacture and in carrying special stock therefor. I

Instead of such armature.- and tator, I prefer to employ a special tator having one or more contact points,

COIllllllliredin series with the terminals of the generator, which is arranged to give alter- .lhe form out commutator actually employed by me in practice has only one point, and it breaks up the alternating current into widely separated periods ;of a single impulse or wave eaclnso that there are no alternations in continuity to start the low. frequency bells to vibrating.

The single point of the commutator makes contactonly once during a complete revolution of the armature, and the duration ct contact is very short. The best results are obtained in an ordinary sized generator with contact 1/16 long on a 5/8 or 3/! diametercommutator.

The current thrown on the line by this commutator apparently has a very high and peaked curve, and while not of suthcirmt volume or strength to operate the ringers it is sutlicient to'operate the switchboard annuneiators with ease.

Bv the use of my new generator All" enabled tojemploy a high Wound bridging switchboard annunciator, thereby prevent ing the shunting of voice current when two parties on the line are talking.

This application is a division oi my for February 1,1907.

My invention is illustratedin the accompanying drawings, in which Figure 1 is a side elevation of my generator. Fig. 2 isanend elevationthereof. Fig. dis a perspective of the separated parts of the commutator and a portion of the ,ar-. mature spindle; Fig. l is a sectional view of one end of the armature spindle and the Patented July 1912.

055.3207 filed commutator. Fig. 5f is a'diagrain of :1. current curve. Fig.6 is a diagrammatic view showing a line, a switchboard drop, three substation ringers bridged across the line, and my improved generator also bridged at a fourth station. Fig. 7 is a similar diagram wit-h the substation ringers in groundv three and to which is secured the plate 2 having apertures at 3 to receive'bolts for attachment to a support. Thepole pieces 4 of the field magnets have secured to them at each end a pair of supporting plates 5 and 6 each provided with an extension in which is journaled the main shaft 7. Carried by the main shaft and meshing with a pinion 8 on the armature shaft 9 is the main or driving gear Wheel, 10 operated in the usual manner by the crank 11. The line contacts 12 and :13 are carried upon a frame 14 secured above the armature shaft 9 on the plate 5 and so positioned as to be engaged by the projecting insulated end 15 .of the shaft 7 when the generator is operated. The end'of the armature shaft 9 is hollowed out and is provided Withan insulating bushing 16 in which the commutator spindle 17 is secured by means of the pin 18 which passes through a bushed' opening in the shaft 9 and is insulated from the shaft by the collar 19. To the end of the commutator spindle 17 is secured the commutator K comprising a pair of metallic disks 20 having projecting teeth 21 and separated by the disk of insulation 22. This disk of insulation is provided with a notch 23 which lies between the two teeth 21 of the disks 20, so as to insure positive contact with the brush 24 carried by the frame 14. The parts 20 and 22 are secured together by bolts 25 passing through-all the disks and electrically connecting the disks 20.

The frame 14 is electrically in connection with the field magnets and supports an arm 27 insulated therefrom but which is in-electrical connection with the spring 13. 1 This arm is provided with a line terminal binding post 26; The other line terminal binding post is indicated at 28 and is formed upon the plate 5-. The brush 24 normally bears against the insulation 22 until the shaft is turned sufiiciently'to bring the lugs 21. of the disks20-in contact therewith at which time the aperture 23 allows the spring to engage said-,lugs. The brush 24 being in engagement with the spring 12 and the spring 13'being at that time forced over into engagement with the spring 12 by the operation of the crank 11 the circuit is thus completed through the generator. This circuit may be traced as follows: binding post 26, arm 27, spring 13, spring 12, brush 24, teeth 21, commutator disks 2(), connector 17 armature winding, frame of generator, end plate 5 to binding post 28. From the time of last contact of the teeth 21 with the brush 24 there is no current whatever passing out over the line as the circuitis broken by reason of the brush engaging the insulating disk 22 and the E. M. F. in the generator piles up so that when the lugs again contact w1th the brqs a high peaked wave as shown in Fig. 5 is trown on the line through the bridge wires.- This current is not of sufficient volume or strength or of long enough duration to'operate the low frequency bells but is strong enough to operate the switchboard drop.

' As shown in Fig; 8, I may arrange the commutating mechanism. upon the crank shaft 7 carries upon its left-hand end a collar 30, which is provided with a projecting tooth or lug 31 adapted to'engage the spring 32 as the shaft 7 is rotated. The spring 32 issecured by screws 33 to an insulating support 34, which in turn is supported from the frame of the generator. The block of insulation 34- also supports the springs 12 and 13, which are adapted to perform the same function as already described. The brush 24 is supported from the insulating block 34 in electrical contact with the spring 12 and is adapted to bear upon a metallic disk 35 secured to the pin 17. The pin 17 is supported from the armature shaft 9 and serves in the same manner to perform the same function as set forth in connection with the form of generator described above. As shown in Fig. 9, the collar 30 may be equipped with two teeth or lugs 31. In this modification the circuit through the generator may be traced as follows: binding post 26, spring 13 spring 12, brush 24, disk 35, pin. 17, to and through the armature wvinding, through the armature shaft, the

frame of the enerator and the crank shaft to collar 30, spring 32, and thus through one of the screws 33 to the'other line connection.

In Fig. 6 I have shown four stations, A, B, C and D, the firstthreeof which are indicated by the bells B and the condensers Cand the last one of which is indicated by the generator heretofore described, in a diagrammatic way. S points out the switchboard drop at the central office, which when the'generator is operated indicates to central that a call has been .made and connection is desired. The binding posts of the generator are connected to the line conductors, asa result of which, when the generator is operated, current takes the following path: from one of the binding posts, through was one line conductor to the signal S, back by the other line conductor to the other binding post of the generator and thence through the generator by a path already traced. The cord circuit-and other apparatus I have not shown as it is deemed unnecessary to the understanding of this invention. In Fig. 7 I have shown a similar system to'that of Fig. 6 except that the stations A B C D E F and G are grounded. As before stated, when a generator as, for instance, that at station D in Fig. 6 was operated the low frequency bells of other subscribers on the same line were operated, resulting in confusion at the substations and also at the central ofiice because the switchboard drop and the low frequency bells were operated simultaneously.

In a modified form of my generator the commutator is mounted on the crank shaftand may be fitted with one or more teeth with the result that without changing the gear ratios ordinarilyused in standard generators and without special formation of the commutator, impulses'of low frequency may be delivered from such generator and that such frequency will not be adapted to operate harmonic ringers. In connection with this form of generator, I have found, however, that without specially designing the gears, the impulses delivered are irregular in value and that in many cases a large number of turns of the crank is required be-. tween impulses of maximum electromotivef force, Thus there is an opportunity for inefficientoperation of the apparatus designed to be actuated by such generator which may, however, be overcome by constructing the commutator on the crank shaft with but one tooth, and by using gears of even ratio. Such an arrangement.- however does notv employ standard gearing, and for this reason I prefer the arrangement already described, in which the commutator is located on the armature shaft and hasbut a single tooth, making contact but once for a short space of time during each rotation of the armature. The point at which this shall occur is definitely fixed, so as to give the proper current effect.

In considering the invention it must be borne in mind that for all harmonic signalmg of successful commercial type, it takes more than a momentary impulse to start vibration of a ringer. This however is also true in many cases ofresonance. The trot of a dog will not at first start a bridge to vibrating, but if maintained for a few seconds it will inevitably do so by reason of the cumulation of energy. It is upon this principle that my present invention is based.

Fig. 5 shows a current curve approximating the wave form produced in my generator. Owing to the sudden discharge when the momentary contact is made at the commutator, there is a jerk or peak which while it runs up high above the neutral line, 'is of small area, and the amount of energy represented is correspondingly small.

While I have shown a bridging circuit, it is to be understood that the generator useful in other circuits, and also that this circuit may be used with other specific forms of generator, so long as the essential principle is employed, of thus preventing resonant efiects. All non-essential changes and departures I include within the scope of my claims.

Having thus described my invention what I claim and desire to secure by Letters Patent is- 1. In a generator for signaling systems, a

field magnet and an armature in operative relation thereto, means for driving such armature, a commutator consisting of a pointed disk connected to such-armature, a brush adapted to bear upon the commutator and means for preventing contact between such brush and such disk except at such pointed portion.

. 2. In a generator for signaling systems, a field magnet and an armature in operative relation thereto, means for driving such armature, a commutator consisting of a disk connected to such armature and having a projecting point, a brush adapted to bear upon such commutator, and means for preventing contact between such brush and such disk except at such projecting point.

In testimony whereof I affix my signature in presence of two witnesses.

RAY II. MANSON.

\Vitnesses:

M. E. TAYLOR, R. G. SANDS. 

